₦airaland Forum

There are many Hadoop flavours but a few standout.
a. Cloudera
b. Hortonworks.

Hadoop itself is an umbrella project for many other projects. It consist of the filesystem(HDFS),query languages(Hive,etc),the core which is the hadoop framework which allows you to write map reduce applications etc.
The benefits of Hadoop is that you can cluster machines and use them for solving time consuming jobs.

Oga dhtml18, you don close class

The whole idea of building a client server architecture as you rightly stated is because server hardware maybe much better than the client hardware. However another important factor for using a client server architecture is because you want to be able to run the client and server over a different network or remotely. Take for example you are in the Lagos and the Machine you want to interact with is in Abuja, even if both have the same processing power. It makes much more sense to use a client-server approach. So i think you need to explain what you want more clearly in your initial posting.
This are some of the reasons to use client-server architecture:
a. Server hardware has unlimited or more resources(CPU,Memory,Storage).
b. Need to work remotely or over a network.
c. The data in question can only be secure if its on a central server. E.g Some applications require additional security and does not make sense to install it on every client pc. Banking app should not be installed on all the cashier pc.
d. The operating system environment may also neccessiate you run a client-server arhcitecture.

Some important notes. For our Customer object, we created a constructor. When creating objects, we may use our constructor to pass parameters to our object variable. This is a clean way of sending data to our objects. Most important to know is that objects are closed systems. One of the ways to inject data into this system is by using constructors.
Lesson Note:
Everyone should create a simple object with any thing that occurs in our every day life. example: Car object,Student Object etc.

Next we need to put some flesh in out Customer object.
PLEASE NOTE THAT WHEN WRITING PYTHON CODE YOU MUST INDENT YOUR CODE PROPERLY.
JAVA is a case-sensitive language
Python:
class Customer:
#our constructor
def __init__(self,firstname,lastname):
self.firstname=firstname
self.lastname = lastname

Java
class Customer{
//Java explicitly requires forward declaration of all variable type;
String firstname;
String lastname;
//our constructor
public Customer(String firstname,String lastname){
this.firstname=firstname;
this.lastname=lastname;
}
}

PHP
class Customer{

$firstname="";
$lastname="";
//our constructor
public Customer($firstname,$lastname){
$this->firstname=$firstname;
$this->lastname=$lastname;
}
}

C#

class Customer{
//C# explicitly requires forward declaration of all variable type;
string firstname;
string lastname;
//our constructor
public Customer(string firstname,string lastname){
this.firstname=firstname;
this.lastname=lastname;
}
}

The idea behind objects is the same thing in every language. What we do with objects is to represent our application in a modular and encapsulated way. Take for example a banking application. We can have the following types of objects:
a. Customer
b. Cashier
c. User
d. Manager
e. BankCommission
f. Transactions
g. Accounts

a simple representation of the Customer object and explanation
Python:
Class Customer:
def __init__(self,firstname,lastname):
self.firstname=firstname
self.lastname=lastname
With this piece of code what we have done is created small part of a customer object. To create an object in most languages(php,python,Java,c#) we use a reserved word called Class. If you dont know what a reserved word is you need to do more research(Reserved words are words that are reserved exclusively for the use by the programming language). The statement
Python
class Customer:
Java
class Customer{}
c#
class Customer{}
php
class Customer{}
This is used to create the base template for our Customer object.

AkunneObinna:
Oh sorry. But do it more gently next time.

Na una sabi. I feel most people feel intimidated when they are corrected. I have met a lot of people on NL who feel they know it all. The know it all attitude is when someone tells u something different you feel intimidated. Programming is a road. You can never ever know it all.

QBasic can actually work with a DBMS but you would have to write the database driver from scratch. Thats not a small job. For a newbie might be very very hard.

d0uph1x:
i know of using text files but i had a problem updating the text file based on users input..thats y i asked d question.

You can use CSV its much easier to manipulate and has structure. CSV file is:
Name,Address,Age
Seun Thomas,Lagos,100
Also i hope this is just school work. QBasic is an ancient of days language.

lekropasky:
ok sis
thanks

Start a project of some sought and follow it to the end by doing more research. If you have a problem along the way, PM me.

dhtml18:
^^^^this is where you should now shine, because you are obviously a computer science person unlike GANGSTAR PROGRAMMER LIKE ME.

Go back to your topic. You follow me come here. Anyway am a gangster programmer too. Fell in love with code along the way sha.

Hello NL, i decided to share my views and my experience on software development. I have been coding for a while and have worked on many projects. Some projects worked fine while others not so fine. Most important lesson i have gotten so far is that programming is a lifelong process. You get better every day. I will start today with an introduction into the concept of an object. But first of all lets start with the rudimentary foundation. A programming language in most cases consist of a runtime(or execution environment) which is the part that takes your code(source code) and converts it to a machine understandable format. A machine(computer,laptop,phone) is actually a very dumb device. It cant do anything on its own. It requires a human to give it the necessary instruction to do something meaningful. Although their are advances in software development that have brought in work such as an intelligent machine(AI,deep learning) but they are not totally autonomous and still require a human. The Other core part of a programming language is the language itself. By the language we mean PHP,Javascript,Java,Assembly,Python,C/C++,C# etc. The language of choice for any programming task depends on the capability of the language as well as the design ideology of the language author. Some languages like Java,C/C++,Python,C# etc are very robust. They can actually work in massive environments. While others may be limited or require extra work to make them work in such environments. I can rightly say that "Not all languages where created equal". Another important note is that machines don't understand code. Machines can only think in digits 1,0,one zero. So basically your programming runtime takes your source code and does the necessary conversion for you.

Now lets go into coding. What is an Object? An object is just a way of abstracting the real from the unreal. The human mind can understand things when they appear more physical or realistic than when they are totally abstract.
Thats why we use objects.
A basic object in some languages would look like this:
Python:

class Person:
def __init__(self,name,age,gender):
self.name=name
self.age=age
self.gender=gender
def setName(self,name):
self.name=name
def getName(self):
return self.name

Java:

class Person(){
String name;
String gender:
int age;
public Person(){

}
public void setName(String name){
this.name=name;
}
public String getName(){
return this.name;
}

}
Basically what we have done is create an object. An object is our way of encapsulating something. We use objects in many cases to hide the real underlying fact about a piece of code. For example we have modeled all the data about a Person in our object. So our object person has a name and an age.

Comment and i will continue on this lesson.

dhtml18:
Na only you waka come o! And I wont mind if you take over the tutorial sef, since you obviously know JAVA/JAVASCRIPT/PHP/ANDROID/IOS BETTER THAN ME.

Bikonu. No vex. You can continue with ya tutorial. I don dey go.

Doctor, i excuse myself from this discussion. Na only me waka come.

AkunneObinna:
.
Oga ThomaS watin be your own?
He wants to teach us something and you are trying to be a hindrance, if you think you know better and can do better go and start up your own thread and tutorial and stop harassing to this beautiful tutorial going on here!!!

My boss DHTML18 please ride on, I am following.

I only expressed my view when he said like "whatsapp".

ballantyne:
Shut up. You aren't. If you were, you wouldn't be on this thread.

Ok sir.

dhtml18:
I shall proceed to ignore everyone that wants to side-track this thread. For those interested, please ignore them.
GET THEE BEHIND ME SATANI! THere IS RAMADAN IS OUTSIDE.

Thanks guys for all those encouraging me. Please note that I actually made a simple chat like this and it works - just that I cannot broadcast it due to certain work ethics code of conduct.
NB: I dont make tutorials on something I have never done. And I dont copy and post stuffs anywhere.


You have just given yourself anyway as being foolish. If the codes do not work, then you say it is bad. In JAVA INTEGER IS MORE POWERFUL and is recommended THAN INT (a relic of the old age, in fact it is primitive and IS NOT AN OBJECT). YOU ARE SO VERY OUTDATED BRO, GO AND LEARN. And there is nothing wrong with my JavaScript - I am one of the best JavaScript coders on the whole of this Nairaland (and possibly in Nigeria) - and I have a lot of work to show for it, so don't even go there at all - i don't wish to embarrass anyone here but i will if i so wish.

There is nothing wrong with your javascript and i did not say there was. But for any of the programming languages you mentioned above(except php), it requires you must do a forward declaration of types. Yes the interpreter would execute your code and infact we all ignore it as developers but trust me whats bad is bad. When you are teaching beginners about programming you need to always state types. As for the Java part, you totally goofed. You may be one of the best programmers on nairaland but you are definately not a good programmer. I am not side tracking you just sharing my views. And next time try to see things from a balanced view. Not everyone who criticises you wants to destroy you. Programming is about criticism the better way of doing things. If you dont know that then you chose a wrong calling.

explain what you mean by "share structure in share memory"

OP I appreciate what you are doing though. Good job.

dhtml18:
I shall complete it. No, you do not need any knowledge of JAVA per say. I shall try to keep everything simple and explain as you go.
Once you know programming, there are just very little differences:

To declare a variable called "age" to hold a number like 10 for example

PHP
$age=10;

Javascript:
age=10;

Java:
Integer age=10;

Once you know at least one programming language - even javascript, you shall be able to follow.

Javascript:
age=10;(bad coding using a var is good)
var age=10;

Java:
Integer age=10;
(bad coding using a built in object where possible)
int age=10;

dhtml18:
^^^I know exactly what you are talking about brother. You can build it and it will work at the basic level, but of course to scale it to thousands and millions of users, you will need something larger like google app engine (i guess we will have a part 2 later on featuring google app engine).
However, this tutorial is targeted at beginners, and the aim of the tutorial is to expose them to technologies. The most important thing in coding practices is your algorithm - once you get it right the first time, it becomes easy for you to scale up.

YOU CANT USE HTTP TO BUILD A LARGE CHAT APP. Its very wasteful. HTTP is stateless. You need to use something like ejabberd(xmpp) or any socket server based system(web socket can work). Also i assume you will be using a RDBMS which would increase latency . So if i send a message now my friend may get it next week if the chat company has 1 million users(just a joking way to explain the reality of this approach). Its a good way to understand how apps work but chat apps are in a different terrain. I know a chat app company that used http and couchbase right now they are going socket server because they know it wont scale.

OP am interested in what you have reversed in c/c++.

dhtml18:
You guys dont sleep ni?

Getting started:
Please note that you can run this tutorial on any pc be it mac/linux/windows, however I shall use windows as the standard.

You need to have the following installed on your pc:
- Notepad++: https://notepad-plus-plus.org/ (optional but recommended)
- wamp server: http://www.wampserver.com/en/ (xamp, easyphp, zend server, ISS or anything that can run php/mysql is fine)
- Java SDK (not JRE o): http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html (compulsory)
- Android studio: http://tools.android.com/download/studio (compulsory)

The idea is that we are going to run everything on your PC, and even test the chat on PC. The final step will include how to setup a web server
online so that multiple users can signin with their devices remotely to chat.

You cant build a chat app like whatsapp using an http server. It wont scale. You can build a very basic chat app though.

elisilver:
i dnt hav any money to host u o

You dont need to have any money to host but you can help us with logistics.

anetuno:
I have said it time and time again that anybody new to programming should start with JavaScript. It is a very good object oriented programming (OOP) and the internet is awash with resources and tutorials on it. It will give you a solid foundation on OOP and you can then move on to Python, Java, C#, etc and you will have fewer questions to ask. After getting grounded in JavaScript, I will recommend you move on to Java, it is the most popular programming language with widespread use.

Dude Javascript OOP is much more difficult than learning python straight up for OOP. But you are right, javascript is a good introductory language for learning programming. I recommend he starts with html+javascript and then he can move to python or c.

yandevboy:
iOS DEVELOPER WANTED for a simple news app.

Contact me if you can do a good job

Interested. Whats your email address?

Yahoo Yahoo Boys.

The stupid man is the one who decides to reinvent the wheel and not build on the wheel. Wise men stand on the shoulders of giants.

Pins:
Frameworks are not a replacement for a programming language,bootstrap is a product of a couple of css and javascript files working together,so is not old school to use html and css3 to design an app or website.

When your boss gives u a deadline or client gives u deadline. Do plain css and html. Dont use bootstrap or any other framework. Also no matter how good your html/css skills are it can never be better that what bootstrap offers. SELAH.

elisilver:
any programming seminar in nigeria especialy rivers state?

I am interested in running one across the country. Would you be interested in hosting us in Rivers State??.

pcguru1:
JavaScript is used to write Node which is used to talk to C++ atom shell/electron all the UI you see are not Native UI they are web pages and and they also bind to Native calls via C++, besides why am i even arguing what is Node built with ? ask yourself that question.

People confuse JS and Node V8 engines, JS is the script chosen to write node apps.

NOTE: I might be wrong so prove me wrong with facts and i will glady accept

Node is a runtime and not a language.